The present invention relates to machines for automatically picking hops from hop vines.
Hops are leafy knotted flowers that grow on vines. Hop vines can grow to a substantial height and will train themselves over any upright support. Commercial growing of hops, therefore, takes advantage of the climbing capability of the vines by allowing the vines to grow up trellises in low rows. The unusual height of the hop vine led, in the past, to a harvest technique of simply cutting the vine at its base and pulling it downwardly off the trellis to gain access to the hops along the full length of the vines. Leaving the vine intact on the trellis, however, is known to favorably affect the yield of the following years crop. Therefore, attempts have been made to produce hop picking machines that will automatically harvest hops from vines still remaining on the trellis.
U.S. Pat. No. 2,447,122 granted to Horst, Jr. et al in 1948 discloses a machine that will move along a row of hop vines to strip hops from the vines. The Horst machine, however, provides a roller that moves along the ground surface, engages the lines at the base, and pulls them downwardly through hop picking fingers. The vines are pulled downwardly and smashed against the ground by the heavy roller. As the vines move downwardly, upwardly moving fingers are used to strip the hops as the vines are pulled downwardly. The hops fall onto a skirting and roll onto substantially horizontal hop collecting conveyors.
There has been recent interest in attempting to harvest hops from vines grown on low profile trellises rather than the tall, traditional hop trellis. A machine developed through conversion of a grape harvesting machine for this purpose included paired, opposed upright hop picking conveyors with outwardly protruding picking fingers. The machine would be driven over the trellis and vine with the picking conveyors situated on opposite sides of the vine. The inwardly facing flights were powered to move the picking fingers continuously upward, lifting the leaves and vines upwardly and stripping the hops from the vines. Such apparatus had many disadvantages. The long hop vines would often wrap over the top of the picking conveyors and the entire hop plant could be forceably uprooted, causing serious harm to the following year's crop. The problem remained, then, of providing an automatic hop picking machine that could effectively clean hops from the hop vines entrained on low profile trellises without doing substantial damage to the vine structure or the trellis.
The present invention is a hop picking machine that enables picking of hops entrained on low profile trellis hop vines without injuring the vine structure or the trellis. The present picking machine includes two sets of picking conveyors. A first longitudinal set of fingers on the first picking conveyor engages the opposite sides of the hop plants and pulls downwardly, stripping hops from the vines in a downward motion. A second set of conveyors follows the first set with upwardly moving fingers. The upwardly moving fingers move along paths that extend above the top of the trellis so the full length of the hop vine can be vertically "strung out" while the hops are being removed therefrom. The vines thus are not capable of wrapping over the top of the picking conveyors and so cannot become entangled and uprooted between the working flights.